similar to: denoting post-hoc test differences using letters

Displaying 20 results from an estimated 7000 matches similar to: "denoting post-hoc test differences using letters"

2011 Jul 26
1
adjusting x-axis labels
I am trying to tweak how my categorical x-axis labels are formatted in my bar graph. Specifically, I would like to a) decrease the spacing between lines (e.g. spacing between Dialium and guianensis) b) right justify the text and c) have each species name align with the center of the corresponding bar graph. A simplified version of my code thus far is as follows. I am using RStudio v.
2011 Jun 21
2
par code help
I am making a barplot using barplot2 from gplots where each bar represents a specific tree species. I have formatted the species names on the x-axis so that the genus name is above the species name and have then rotated the labels 45 degrees to save room. This is my code: >columncolor<-c("grey20", "grey20", "grey20", "grey70",
2011 May 23
2
Formatting names.arg
I am making a barplot using barplot2 from gplots and would like to format the names of my categorical variables (tree species) on the x- axis so that the genus name is above the species name (to save room). My code so far is: speciesnames<-c("Dialium guianensis", "Inga alba", "Tachigali versicolor", "Brosimum utile", "Caryocar
2010 Jun 05
1
selecting only specific rows in R
Hi, I have a data frame with columns as follows: tree species (independent variable) and several dependent variables (e.g. carbon, nitrogen, phosphorus). Each row represents one tree sample. Some tree samples are unique species in the data frame while other species were replicated (i.e. rows 1,2,3 may be identical for the "tree species" column but have different values for the
2011 Jun 10
2
Problem loading packages in R 2.13.0 on Mac
I am having problem loading packages in the newest version of R (2.13.0) on my Mac. I have tried to install various packages (e.g. lawstat, Rcmdr, car) and load them using the Package Installer and Package Manager menu options but I get the follow error: > library(lawstat) Loading required package: mvtnorm Error: package 'mvtnorm' could not be loaded In addition: Warning
2012 Oct 19
2
Post Hoc tests for ANOVA
Hi, I was trying to figure out how to do post-hoc tests for Two Way ANOVAs and found the following 2 approaches: a. Do pairwise t-tests (bonferroni corrected) if one finds significance with the ANOVA. Link- http://rtutorialseries.blogspot.com/2011/01/r-tutorial-series-two-way-anova-with.html b. Do TukeyHSD on an aov model Link-
2005 Oct 26
1
Post Hoc Groupings
Quick question, as I attempt to learn R. For post-hoc tests 1) Is there an easy function that will take, say the results of tukeyHSD and create a grouping table. e.g., if I have treatments 1, 2, and 3, with 1 and 2 being statistically the same and 3 being different from both Group Treatment A 1 A 2 B 3 2) I've been stumbling over the proper syntax for simple effects for a tukeyHSD
2008 Aug 15
1
post hoc tests two way repeated measures anova
Hi, is there a specific/appropriate function/package to perform post hoc tests when running a two way repeated measures anova? I'm looking for something that will be equivalent to the 'TukeyHSD()' for between subjects anova (with 'aov()'). For one way repeated measures anova, the 'pairwise.t.test()' function seems to work correctly but the results are questionable for
2006 Apr 06
1
recommendation for post-hoc tests after anova
Greetings all, I've done some ANOVAs and have found significant effects across my groups, so now I have to do some post-hoc tests to ascertain which of the groups is driving the significant effect. Usually one would do something like a Newman-Keuls or Scheffe test to get at this but based on googling and browsing through the r-help archives R doesn't support these and they seem to be
2004 Sep 24
1
anova and post hoc multicomparison tests
Hello everyone, Like a lot of people, I have been looking for functions in R doing ANOVA (ok) and performing multicomparisons (like Student-Newman-Keuls, etc.). As I have been a little bit disappointed, I have bee looking through the net for such "open source" softwares. I found one in: http://www.statpages.org/miller/openstat/OS4.html I have begun to use it, and it seems good and
2008 Apr 29
0
Looking for Post-hoc tests (a la TukeyHSD) or interaction-level independent contrasts for survival analysis.
Hello all R-helpers, I've performed an experiment to test for differential effects of elevated temperatures on three different groups of corals. I'm currently performing a cox proportional hazards regression with censoring on the survivorship (days to mortality) of each individual in the experiment with two factors: Temperature Treatment (2 levels: ambient and elevated) and
2010 Jan 11
1
matchname messages filling logs - howto stop?
Listmates, I have had a few boxes where the 'matchname' message is filling my syslog with one new message ever ~40 seconds or so. No performance problems, just the log annoyance. An example of the messages are: Jan 11 13:43:03 nemesis smbd[2246]: [2010/01/11 13:43:03, 0] lib/util_sock.c:1685(get_peer_name) Jan 11 13:43:03 nemesis smbd[2246]: Matchname failed on Adrienne-PC.rbpllc.com
2001 Feb 27
4
Post hoc tests
This is only partly an R question, but this seems a good place to ask. Like many, if not most, statistics programs, R has no post hoc tests for Kruskal Wallis or Friedman, and as far as I can make out they are not available in any of the R packages. I would be grateful if someone could point me in the right direction if I am wrong. As I said this is not uncommon. Parametric Anova procedures
2011 Jun 12
1
welch anova and post-hoc
dear r community... it loks like i won't be able to reach homogenity of variance for my dataset, so i end up with welch anova instead of regular anova. documentation on this test is rather scarce, so maybe someone here can enlighten me a bit: - do i understand that no two-way implementation of the welch anova has been developed yet? - is there a post-hoc test for welch anovas implemented in
2010 Nov 01
1
ggplot map bounds
To all, I'm working with code below to produce a map with station data plotted in points, but right now I'm having trouble with the mapping portion of this code states <- data.frame(map("state", plot=FALSE,xlim= c(-85,-75),ylim=c(33,37))[c("x","y")]) usamap<- ggplot(states)+geom_path(aes(x,y)) usamap When I plot this the problem is that the bounds of
2012 Jan 02
1
Is using glht with "Tukey" for lme post-hoc comparisons an appropriate substitute to TukeyHSD?
Hello, I am trying to determine the most appropriate way to run post-hoc comparisons on my lme model. I had originally planned to use Tukey HSD method as I am interested in all possible comparisons between my treatment levels. TukeyHSD, however, does not work with lme. The only other code that I was able to find, and which also seems to be widely used, is glht specified with Tukey:
2010 Jun 06
1
Why did TukeyHSD not work when I used it for post-hoc for 2way within-subjects anova?
Dear R people, I have a couple of questions about post-doc analyses for 2 by 2 within subjects ANOVA. I conducted a psycholinguistic study that combined a 2 by 2 design and a latin square design. Specifically, I had 32 items each of which generated 4 conditions. Participants saw each of the 32 items only once: 8 in Condition A, 8 in B, 8 in C, and 8 in D. The table below serves as an example.
2011 Dec 12
3
windrose color ramp issue
Greetings! I'm having an issue with the windrose produced by the windrose function from the circular package. For our weather stations in North Carolina I'm helping with a script which takes hourly wind speed and direction data to create windroses for our end users. One of the stations in the mountains frequently reaches wind speed of 40 to 60 mph and in storms can reach wind speed over
2005 Nov 25
1
optim
Hello: I am trying to use optim() to estimate the maximum likelihood of a function a*x^b = y. Unfortunately, I always get the error, that there is no default value for b. Could you give me an example, on how to correctly optimize this function with input data x<-c(1,3,11,14). Thanks a lot, Adrienne -- *********************************************************************** Adrienne
2018 Jan 16
1
Letters group Games-Howell post hoc in R
Hello everybody, I use the sweetpotato database included in R package: data(sweetpotato) This dataset contains two variables: yield(continous variable) and virus(factor variable). Due to Levene test is significant I cannot assume homogeneity of variances and I apply Welch test in R instead of one-way ANOVA followed by Tukey posthoc. Nevertheless, the problems come from when I apply posthoc